Internal batch mixing machines with non-intermeshing rotors of increased

Abstract

Non-intermeshing four-wing and three-wing rotors for use in high intensity mixing machines of the batch type provide new sequences and new characteristics of dynamic interactions for achieving advantageously increased mixing effectiveness and strength of the rotors. These new rotors are adapted for driving at unequal speed (unsynchronized rotation) or at equal speed (synchronized rotation). In the four-wing rotors, long wings and short wings both originate from both ends of the rotor. The new four-wing and three-wing rotors intensify axial mixing action and transverse distributive mixing for causing the mixes (batches) to become more homogeneous. The markedly increased twist angles T in both types of rotors decreases the volume of material 'sitting' at the center of the mixer for maximizing the dispersive mixing or high shear occurring between wing tips and wall surface of each rotor cavity. The marked increase in helix angles A enhance distributive (blending) mixing by rolling banks of material in axial directions in the rotor cavities with components of axial movement and axial flow. The larger ratios of axial wing length to rotor length increase the propelling of material from near the originating end of the long wing in an axial direction along the cavity over near to the other end of the cavity and then back again with back-and-forth zig-zag like motions for enhancing distributive mixing and blending. Randomization of blending is advantageously achieved by each rotor by rolling the banks of material back-and-forth with differing velocities in opposite directions. The new interactions of these rotors produce numerous advantages and mixing features.